This is Terrye Newkirk with her hit "My Oklahoma," which has been covered by many folks, including her now ex-husband Steve Young ("Seven Bridges Road"), and their son, Jubal Lee Young, as well as Riders in the Sky, and others.
Oh, and she was singing partners with Roger Tillison, and worked with Bob Dylan, Leon Russell, JJ Cale, and others.
Aw, what the heck...this is Terrye's ex, Steve Young, singing her song. It was on his 7 Bridges Road LP, but I'm not sure if this is that version or not. I think there's a cover where he and their son, country star Jubal Lee, are singing "My Oklahoma." In the mean time: